The invention relates to a cleaning device for cleaning a fuser roller that fixes a toner image on recording paper, and a fusing device, and an image forming apparatus, provided with the cleaning device.
A recent type of cleaning device employs a roll of sheet of fiber cloth impregnated with oil for removing toner debris on an outer surface of the fuser roller (See JP 2003-107952A). This roll of fiber cloth sheet is referred to as a cleaning web. Generally, this type of cleaning device is provided with a supply roller with an unused cleaning web wound thereon, a take-up roller for pulling and taking up the web withdrawn from the supply roller, a tension roller for pressing a portion of the web against the fuser roller.
While the take-up roller is fixed, the web rubs at the outer surface of the rotating fuser roller, thereby removing toner particles that remain on the surface of the fuser roller. Most of the toner particles removed from the fuser roller develop up between the web and the surface of the fuser roller at the side of the take-up roller.
A specified length of the web is pulled by the take-up roller and wound thereon each time after a predetermined number of image forming processes are performed. As the web is pulled and wound, the developed-up toner particles adhere to the web and is thereby collected.
If the developed-up toner particles are larger in amount than the toner particles collected by the web, however, the developed toner particles are left uncollected. Since most cleaning webs are impregnated with silicon oil, toner particles that have been left uncollected for too long between the web and the fuser roller become slippery with the oil from the web. Thus, some of the slippery toner particles may pass through a gap between the fuser roller and the web and adhere to recording paper in touch with the fuser roller.
Meanwhile, if an increased length of the web is pulled by and wound on the take-up roller to avoid the above-described problem, consumption of the web undesirably increases.
A feature of the invention is to provide a cleaning device that prevents toner particles from being left uncollected for too long between a cleaning web and a fuser roller while preventing an increase in web consumption, and a fusing device, and an image forming apparatus, provided with the cleaning device.